Modern Vespa

All - Looking for instructions on how to tackle replacing the front brake pads on my GTS 250. And any common mistakes to avoid. Tried searching, but didn't really find what I was looking for.

Thanks.

It's very simple. Take the tire off, take the caliper off.Force the shoes apart with a screwdriver.
If you've topped up the brake fluid while you had worn pads in there, you might have a problem getting the pucks in the caliper all the way back, because as you lose material, the fluid level goes down.
Take out the pin, drop them out, put the new ones in, put the pin back in, and mount the caliper on the fork. Then put the tire back on, and PUMP THE BRAKES until they feel normal again. If you don't, and you take it for a ride, you better not need to stop in a hurry.

I might suggest getting a tooth brush and degreaser and clean the caliper really well. Qtips would help too. Rotate the pistons. I would clean the pad pin, polish it to a fine finish. Install new pads after you do all that.
You can lube the caliper seals with some brake caliper seal grease or just a dab of brake fluid on a Q tip.
On the rotors you can run some 150 emry cloth and do a final clean with brake cleaner & lint free towel.